True Televisions have the CRT Tube !!
Welcome to the Obsolete Technology Tellye Web Museum. Here you will see a TV Museum showing many Old Tube Television sets
all with the CRT Tube, B/W ,color, Digital, and 100HZ Scan rate, Tubes technology. This is the opportunity on the WEB to see, one more time, what real technology WAS ! In the mean time watch some crappy lcd picture around shop centers (but don't buy them, or money lost, they're already broken when new) !!!

Richtige Fernseher haben Röhren!

Richtige Fernseher haben Röhren!

In Brief: On this site you will find pictures and information about some of the electronic, electrical and electrotechnical technology relics that the Frank Sharp Private museum has accumulated over the years .

Premise: There are lots of vintage electrical and electronic items that have not survived well or even completely disappeared and forgotten.

Or are not being collected nowadays in proportion to their significance or prevalence in their heyday, this is bad and the main part of the death land. The heavy, ugly sarcophagus; models with few endearing qualities, devices that have some over-riding disadvantage to ownership such as heavy weight,toxicity or inflated value when dismantled, tend to be under-represented by all but the most comprehensive collections and museums. They get relegated to the bottom of the wants list, derided as 'more trouble than they are worth', or just forgotten entirely. As a result, I started to notice gaps in the current representation of the history of electronic and electrical technology to the interested member of the public.

Following this idea around a bit, convinced me that a collection of the peculiar alone could not hope to survive on its own merits, but a museum that gave equal display space to the popular and the unpopular, would bring things to the attention of the average person that he has previously passed by or been shielded from. It's a matter of culture. From this, the Obsolete Technology Tellye Web Museum concept developed and all my other things too. It's an open platform for all electrical Electronic TV technology to have its few, but NOT last, moments of fame in a working, hand-on environment. We'll never own Colossus or Faraday's first transformer, but I can show things that you can't see at the Science Museum, and let you play with things that the Smithsonian can't allow people to touch, because my remit is different.

There was a society once that was the polar opposite of our disposable, junk society. A whole nation was built on the idea of placing quality before quantity in all things. The goal was not “more and newer,” but “better and higher" .This attitude was reflected not only in the manufacturing of material goods, but also in the realms of art and architecture, as well as in the social fabric of everyday life. The goal was for each new cohort of children to stand on a higher level than the preceding cohort: they were to be healthier, stronger, more intelligent, and more vibrant in every way.

The society that prioritized human, social and material quality is a Winner. Truly, it is the high point of all Western civilization. Consequently, its defeat meant the defeat of civilization itself.

Today, the West is headed for the abyss. For the ultimate fate of our disposable society is for that society itself to be disposed of. And this will happen sooner, rather than later.

OLD, but ORIGINAL, Well made, Funny, Not remotely controlled............. and not Made in CHINA.

How to use the site:

- If you landed here via any Search Engine, you will get what you searched for and you can search more using the search this blog feature provided by Google. You can visit more posts scrolling the left blog archive of all posts of the month/year,or you can click on the main photo-page to start from the main page. Doing so it starts from the most recent post to the older post simple clicking on the Older Post button on the bottom of each page after reading , post after post.

You can even visit all posts, time to time, when reaching the bottom end of each page and click on the Older Post button.

- If you arrived here at the main page via bookmark you can visit all the site scrolling the left blog archive of all posts of the month/year pointing were you want , or more simple You can even visit all blog posts, from newer to older, clicking at the end of each bottom page on the Older Post button.So you can see all the blog/site content surfing all pages in it.

- The search this blog feature provided by Google is a real search engine. If you're pointing particular things it will search IT for you; or you can place a brand name in the search query at your choice and visit all results page by page. It's useful since the content of the site is very large.

Note that if you don't find what you searched for, try it after a period of time; the site is a never ending job !

Every CRT Television saved let revive knowledge, thoughts, moments of the past life which will never return again.........

Many contemporary "televisions" (more correctly named as displays) would not have this level of staying power, many would ware out or require major services within just five years or less and of course, there is that perennial bug bear of planned obsolescence where components are deliberately designed to fail and, or manufactured with limited edition specificities..... and without considering........picture......sound........quality........

Thursday, April 7, 2011

SALORA 15L30 Type L30A CHASSIS L CRT TUBE TOSHIBA A36JAR40X03

CRT TUBE TOSHIBA A36JAR40X03

TOSHIBA UNITIZED Electron gunAn
electron gun comprising a plurality of focusing grids spatially
arranged along the path of an electron beam generated from a cathode and
each bored with at least one opening for allowing the passage of the
electron beam, wherein at least one of said plural focusing grids is
formed of at least one electrode set at a grounding potential or a
lower potential than a focusing voltage and at least one more
electrode whose potential is defined by an electrostatic capacity; and
a high voltage is produced to provide an electron lens, though
enabling the electron lens to improve its performance without being
obstructed by requirements associated with the construction of a
picture tube.

1. An electron gun comprising a
plurality of focusing grids spatially arranged along the path of an
electron beam generated from a cathode and each bored with at least
one opening for allowing passage of the electron beam, wherein at
least one of said plural focusing grids is formed between two other
grids and includes a second electrode set at a grounding potential or a
lower potential than a focusing voltage, and first and third
electrodes arranged on opposite sides of said second electrode along
the electron beam path and electrically connected with each other,
the potentials of said first and third electrodes being defined by
the potentials of said two other grids and the potential of said
second electrode and by the capacitance between said first electrode
and the adjacent other grid, the capacitance between said first
electrode and said second electrode, the capacitance between said
third electrode and the adjacent other grid and the capacitance
between said third electrode and said second electrode.
2. The electron gun according to claim 1,
wherein the second electrode is grounded through a variable
capacitor.

Description:

BACKGROUND OF THE INVENTION
This
invention relates to an electron gun for generating one or more
electron beams and more particularly to an electron gun provided with
means for effectively focusing the electron beams on a target.
With
the ordinary color picture tube provided with a multi-beam electron
gun designed to generate a plurality of electron beams, the
respective electron beams pass through separate electron lenses to be
focussed at a point on a target. The electron lens is generally
formed of a static electric field to focus the electron beams at a
single point. The static electric field is formed at right angles to
an electron beam path, and is disposed between at least two
electrodes each bored with an opening allowing the passage of an
electron beam. The properties of the electron lens can generally be
varied according to interelectrode voltage, the size of an opening
bored in the electrodes and a distance therebetween.
The
electron gun is generally regarded to have a more improved
performance, according as the electron lens is more reduced in the
degree of magnification and spherical aberration. To provide an
electron gun of high quality, therefore, it is necessary to extend
the focal length of the electron lens. The most effective process to
attain this object is to vary interelectrode voltage. However, the
level of the interelectrode voltage should generally be restricted to
fall within such a range as prevents arcing from taking place at the
base portion of a picture tube. Further, enlargement of an electrode
opening to extend the focal length of the electron lens is subject
to certain limitations, because the neck diameter of the picture tube
is restricted by other electrical requirements. Moreover, extension
of the interelectrode distance is not advisable since the properties
of the electron lens are harmfully affected by a electric charge
occurring in the neck portion of the picture tube and the generation
of an unnecessary electric field in the electron gun. As mentioned
above, the design of the electron lens is subject to limitations due
to various physical requirements associated with the construction of a
picture tube. These limitation are particularly rigid in the case of
a color picture tube using a multi-beam electron gun.
The
customary process of manufacturing an electron lens having a long
focal length without being obstructed by the above-mentioned
limitations is to combine properly interelectrode voltage and the kind
of electrode. An electron gun constructed by the above-mentioned
process has already beam set forth in the Japanese patent disclosures
Nos. 76072/1976 and 77061/1976.
However, the disclosed
processes have the drawbacks that the electron gun unavoidably has a
complicated construction and extra voltage has to be applied to
improve the formation of an electron lens, thus leading to economic
disadvantage. For elevation of the performance of an electron lens, it
is necessary to apply high voltage with respect to not only the
electron guns used in the above-mentioned disclosed processes but also
electron guns in general use. In such a case, a special device has to
be provided to suppress arcing which might otherwise occur in the
base portion of a picture tube in order to ensure its reliable
operation, thus rendering the picture tube more expensive.
SUMMARY OF THE INVENTION
It
is accordingly the object of this invention to provide an electron
gun admitting of the elevation of the performance of an electron lens
without being obstructed by requirements associated with the
construction of a picture tube.
According to this invention,
there is provided an electron gun comprising a plurality of focusing
grids spatially arranged along the path of an electron beam generated
from a cathode and each bored with at least one opening for allowing
the passage of the electron beam, wherein at least one of said plural
focusing grids is formed of at least one electrode set at a
grounding potential or a lower potential than the focusing voltage
and at least one more electrode whose potential is defined by an
electrostatic capacity.
BRIEF DESCRIPTION OF THE DRAWING
FIG. 1A is a front view of an electron gun according to one embodiment of this invention;
FIG. 1B is a plan view of the electron gun of FIG. 1A;
FIG. 2 is a sectional view of the electron gun of FIG. 1A;
FIG. 3 shows an equivalent circuit of the electron gun of FIG. 2;
FIG. 4 is a sectional view of a modification of a fourth focusing grid used with the electron gun of FIG. 2;
FIG. 5 schematically illustrates a modification of the electron gun of FIG. 1; and
FIG. 6 is a sectional view of an electron gun according to another embodiment of this invention.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
For an electron gun embodying this invention,
there is applied an entirely novel process never known to date which
utilizes an electrostatic capacity of an electrode to apply voltage
on said electrode. Therefore, an electron lens can be designed to act
as a high voltage electrode, though actually a much lower voltage is
externally applied.
There will now be described by reference
to the accompanying drawing the cases where this invention is
applied to a uni-potential type electron gun and a bi-potential type
electron gun. Description is first given of the case where this
invention is applied to the uni-potential type electron gun. FIGS.
1A, 1B and 2 are respectively a front view, plan view and sectional
view of an in-line type electron gun used with a color picture tube.
An electron gun 1 comprises a plurality of electrodes and glass
supports thereof. The plural electrodes constitute these cathodes 2,
3, 4, first grid 5, second grid 6, third grid or first focusing grid
7, fourth grid or third focusing grid 8 and fifth grid or second
focusing grid 9. These grids are fitted to the glass supports 10 in
the order mentioned as counted from the cathode side. The cathodes 2,
3, 4, send forth electron beams along three paths lying on the same
plane. The first grid 5 and second grid 6 are flat electrodes closely
facing each other and are respectively bored with a group of three
openings 11-12-13 and another group of three openings 14-15-16 which
are aligned with the three electron beam paths. The third grid or
first focusing grid 7 is positioned adjacent to the second grid 6.
The grid 7 is formed of a pair of cups 20, 21 joined with each other
on the peripheral edges of the openings thereof. The bottoms of said
cups 20, 21 are respectively bored with a group of three openings
17-18-19 and another group of three openings 22, 23, 24 which are
aligned with the three electron beam paths. The openings 17, 18, 19
of the first cup 20 have a larger diameter than the openings 14, 15,
16 of the second grid 6. The openings 22, 23, 24 of the second cup 21
have a larger diameter than the openings 17, 18, 19 of the first cup
20. The fourth grid or third focusing grid 8 is formed of at least
three auxiliary electrodes 25, 26, 27. The first electrode 25 and
third electrode 27 are respectively formed of a pair of cups joined
with each other. Both electrodes 25, 27 are respectively bored with a
group of three openings 28-29-30 and another group of three openings
33-34-35 which are aligned with the three electron beam paths. Said
electrodes 25, 27 are electrically connected together to have the
same potential, and spatially arranged along the electron beam paths.
Provided between the electrodes 25, 27 is a plate-shaped second
electrode 26, which is also bored with three openings aligned with
the three electron beam paths. The fifth grid or second focusing grid
9 is cup-shaped, spaced from the fourth grid 8 substantially as much
as a distance between the third grid 7 and fourth grid 8, and also
bored with three openings 36, 37, 38. The central opening 37 is
aligned with the axis 43 of the central opening of the first grid 5
to that of the fourth grid 8. But the other openings 36, 38 are
respectively slightly displaced outward from the axes 44 of the side
openings of the first grid 5 to that of the fourth grid 8. The
displacement is intended to cause two electron beams other than the
central one to be slightly deflected by an asymmetrical electric field
in order to converge the three electron beams at a single point on a
target. The fifth grid or second focusing grid 9 is fitted with a
cylindrical shield cup 42 whose bottom is bored with three openings
aligned with the three electron beam paths. A plurality of bulb spacers
45 made of a metal strip are mounted on the edge of the open side of
the cylindrical shield cup 42.
The grids of the electron gun are spaced from each other as follows.

______________________________________

A
distance between the third grid or first focusing grid 7 and the
first electrode 25 of the fourth grid or about 1 mm third focusing
grid 8 A distance between the third electrode 27 of the fourth grid
or third focusing about 1 mm grid 8 and the fifth grid or second
focusing grid 9 A distance between the second electrode 26 and the
first electrode 25 of the about 0.6 mm fourth grid or third focusing
grid 8 A distance between the second electrode 26 and the third
electrode 27 of the about 0.6 mm fourth grid or third focusing grid 8

______________________________________

The
third grid 7 and fifth grid 9 are electrically connected together to
have the same potential. The second electrode 26 of the fourth grid 8
is electrically insulated from the first electrode 25 and third
electrode 27 of said fourth grid 8, and is set at a grounding
potential or externally applied with a prescribed value of voltage
when the electron gun is put into operation. However, the first
electrode 25 and third electrode 27 of said fourth grid 8 are not
externally supplied with any voltage.
When an electron gun is
built in a picture tube, the bulb spacers 45 are pressed against the
inner wall of the picture tube, thereby electrically connecting the
fifth grid 9 to the inner wall of the picture tube. During the
operation of the electron gun, the third grid 7 and fifth grid 9 are
applied with voltage of about 25 to 30 kv through the inner wall of
the picture tube. The second electrode 26 of the fourth grid 8 is
grounded through the base portion of the picture tube. At the time,
the first electrode 25 and third electrode 27 of the fourth grid 8 are
naturally applied with voltage of about 10 kv. The reason why this
voltage is naturally generated in the first and third electrodes 25,
27 of the fourth grid 8 may be explained as follows by reference to
the equivalent circuit of FIG. 3.
Two capacitors C 1
of FIG. 3 are respectively formed between the third grid 7 and the
first electrode 25 of the fourth grid 8, and also between the third
electrode 27 of the fourth grid 8 and fifth grid 9. Two other
capacitors C 2 are produced between the first and second
electrodes 25, 26 of the fourth grid 8, and also between the second
and third electrodes 26, 27 of said fourth grid 8.
Referring to the equivalent circuit of FIG. 3, the two capacitors C 1 and the two other capacitors C 2 are respectively connected in series. The character M 1 denotes the third grid 7; the character M 2 the fifth grid 9; the charactor L 1 the first electrode 25; the character L 2
the third electrode 27; and the character N the second electrode 26.
Where voltage of, for example, 25 kv is applied on the third grid 7
or M 1 and the fifth grid 9 or M 2 , and the
second electrode 26 or N is set at a grounding potential, then voltage
corresponding to the capacities of two capacitors C 1 , C 2 constituting one set is generated in the first electrode 25 or L 1 , and voltage corresponding to the capacities of two capacitors C 1 , C 2 constituting another set is generated in the third electrode 27 or L 2 . The capacities of the capacitors C 1 , C 2
are defined only by a distance between the respective electrodes
constituting said capacitors, if the electrodes have substantially the
same shape. Where, therefore, levels of voltage being applied on the
first and third electrodes 25, 27 of the fourth grid 8 are selected in
designing an electron gun, then a ratio which a distance between the
electrodes constituting the capacitor C 1 bears to a distance between the electrodes constituting the capacitor C 2
is defined. Conversely speaking, where the ratio between said
distances is chosen, then values of voltage applied on the first and
third electrodes 25, 27 of the fourth grid 8 are determined. Values of
the above-mentioned voltage and distance are practically decided as
follows. An electron gun in which all the electrodes constituting the
fourth grid 8 have the same potential represents the ordinary
uni-potential type. Where this type of electron gun is designed by
setting the focusing voltage (voltage impressed on the fourth grid 8)
at 10 kv when voltage of 25 kv is applied on the third and fifth grids
7, 9, then it is advised to set a distance between the first and
second electrodes 25, 26 of the fourth grid 8 and that between the
second and third electrodes 26, 27 thereof and ground the second
electrode 26. Assuming that a distance between the third grid 7 and
first electrode 25, and a distance between the fifth grid 9 and third
electrode 27, that is, distances between the electrodes respectively
constituting the two capacitors C 1 are chosen to be 1
mm, then a distance between the first and second electrodes 25, 26 of
the fourth grid 8 and a distance between the second and third
electrodes 26, 27 thereof, that is, distances between the electrodes
respectively constituting the two other capacitors C 2 are calculated to be 0.67 mm, as measured from the following equation: ##EQU1##
What
should be taken into consideration in adopting the above-mentioned
method of designing an electron gun, is to prevent the potential of
the second electrode 26 of the fourth grid 8 from exerting a harmful
effect on an electron lens. Namely, it is necessary, for example, to
bore the second electrode 26 of the fourth grid 8 with three openings
larger than those of the first and third electrode 25, 27 thereof
and, where required, construct the fourth grid 8 as illustrated in
FIG. 4, thereby preventing an electrostatic field created by the
second electrode 26 from substantially exerting a harmful effect on
the function of an electron gun particularly, an electron lens. The
fourth grid of FIG. 4 is formed of a first electrode 47, second
electrode 48 and third electrode 49. The peripheral edges of the
three openings bored in the first electrode 47 and those of the third
electrode 49 projects towrard the second electrode 48. If however,
an electrostatic field generated in the neighborhood of the second
electrode does not substantially exert any harmful effect on the
function of an electron lens, then it is unnecessary to construct the
fourth grid 8 as shown in FIG. 4. It is obviously possible
positively to utilize an electrostatic field produced in the
proximity of the second electrode 48. In such case, the
interelectrode distance can not be determined by the previously
described method.
Rigidly speaking, an electrostatic capacity
is not defined solely by a distance between two mutually facing
electrodes or other factors thereof, but is actually affected by the
properties of other electrodes and earth capacity. Practically,
therefore, a proper interelectrode distance has to be experimentally
determined.
FIG. 5 schematically shows the arrangement of a
modification of focusing means used with an electron gun embodying this
invention. This focusing means is formed of a first focusing grid
52, second focusing grid 53 and third focusing grid 54. The first
focusing grid 52 is bored with three openings aligned with three
electron beam paths. The second focusing grid 53 is bored, like the
first focusing grid 52, with three openings aligned with three
electron beam paths, and further fitted with a shield cup 57. The
third focusing grid 54 is formed of an inner annular auxiliary
electrode 55 disposed substantially halfway between the first and
second focusing grids 52, 53 along an electron beam path and an outer
annular auxiliary electrode 56 positioned coaxially with the inner
annular auxiliary electrode 55 spatially to surround it. The inner
annular auxiliary electrode 55 is not externally impressed with
voltage. The outer annular auxiliary electrode 56 is set at a
grounding potential. With the focusing means of the above-mentioned
construction, the potential of the inner annular auxiliary electrode
55 is substantially defined by an electrostatic capacity generated
between the first and second focusing grids 52, 53 and an
electrostatic capacity produced between the inner annular auxiliary
electrode 55 and outer annular auxiliary electrode 56.
The
foregoing description relates to the case where this invention was
applied to a uni-potential type electron gun. There will now be
described by reference to FIG. 6 the case where the invention is applied
to a bi-potential type electron gun. The electron gun of FIG. 6
comprises a cathode 60, first grid 61, second grid 62, first focusing
grid 63 and second focusing grid 64 which are arranged in the order
mentioned as counted from the cathode side, and each bored with one
opening aligned with a common electron beam path. The first focusing
grid 63 is formed of at least three electrodes, namely, first electrode
65, second electrode 66 and third electrode 67. With a bi-potential
type electron gun constructed as described above, the second focusing
grid 64 is applied with the final electron beam-accelating voltage
(for example, 25 kv) of a picture tube. The second grid 62 is
generally applied with voltage of about 500 v. With the ordinary
bi-potential type electron gun, the first focusing grid 63 is applied
with voltage of 3 to 4 kv. With a bi-potential type electron gun
embodying this invention, however, it is only necessary to impress
low voltage of, for example, 500 v or grounding voltage on the second
electrode 66 and connect together the first and third electrodes 65,
67 disposed on both sides of the second electrode 66 with the same
potential. Namely, the first and third electrodes 65, 67 are not
externally impressed with any voltage. The potential of the mutually
connected first and third electrodes 65, 67 is defined by the
potentials of the second focusing grid 64, second electrode 66 and
second grid 62 and the capacitances C 1 , C 2 , C 3 , C 4
generated between the respective electrodes (FIG. 6). The
interelectrode distance is determined by the similar method to the
aforementioned embodiment. Since the capacitances C 1 to C 4 vary with the shape of the corresponding electrodes, it should be defined with said variation taken into account.
With
the bi-potential type electron gun of FIG. 6 embodying this
invention, a sort of uni-potential electrostatic lens is formed in the
first focusing grid 63. Therefore, electron beams are subjected to a
certain degree of focusing while passing through the openings of the
first focusing grid 63, thereby improving the focusing property of
the bi-potential type electron gun of FIG. 6 over that of a similar
type of electron gun in which the above-mentioned uni-potential
electrostatic lens is not produced. Unless required, it is obviously
possible to change that portion of the first focusing grid 63 in which
the above-mentioned uni-potential electrostatic lens is produced
into such shape as prevents electron beams from being focusing.
As
described above, this invention makes it possible to elevate
electron lens-forming voltage whose level has hitherto been subject
to certain limitations due to requirements associated with the
construction of a picture tube, thereby improving the function of the
electron lens.
Namely, with the electron gun of this
invention, high electrode voltage is indeed applied to increase the
performance of an electron lens. To this end, however, much lower
voltage has only to be externally applied, thereby eliminating
arcings at the base portion of a picture tube which have hitherto
raised problems. Further advantages of the invention are that since
an external power source need
not generate high voltage, the arrangement of a picture tube circuit
is simplified, decreasing the power consumption of said circuit; and
since the base portion of the picture tube is not applied with high
voltage, the picture tube can be operated more reliably, making it
possible to design the base portion so as to ensure the reduction of
cost. With the first embodiment of FIG. 2 relative to a uni-potential
type electron gun, the second electrode 26 was set at a grounding
potential. With the second embodiment of FIG. 6 relative to a
bi-potential type electron gun, the second electrode 66 is impressed
with low voltage of, for example, 500 v. With either type of electron
gun, the second electrode may be set at a grounding potential or be
impressed with low voltage. Where, as show in FIG. 6, the second
electrode is set at a grounding potential, provision of a variable
capacitor 68 between the second electrode 66 and the grounding electrode
outside of the picture tube makes it possible to control focusing
voltage, if necessary. Further, insertion of a high resister between
the second electrode and grounding electrode, though not changing the
focusing voltage, has the advantage that should a arcing take place
in a picture tube, said high resistor acts as a damping resistor,
minimising the generation of arc current and saving the cathode from
damage and other difficulties.
The first embodiment relates to
a uni-potential type electron gun provided with three in-line
cathodes. The second embodiment relates to a bi-potential type electron
gun comprising a single cathode. Obviously the type of electron gun
and that of cathode can be freely combined. The point is that this
invention is applicable to any type of electron gun, provided the
focusing electrode or grid can be used as a capacitor type. With the
foregoing embodiments, electrodes aligned with electron beam paths were
utilized as the capacitor electrodes. However, application of this
invention need not be limited to such type of electron gun. Namely,
the electron gun of, for example, FIG. 2 may comprise a second
cylindrical electrode which encloses a fourth grid and is bored with
three openings aligned with three electron beam paths. In this case,
an electron lens has its inner diameter reduced. Therefore, the
electron lens should be constructed in consideration of the result of
comparison between the effect of the voltage supplied thereto and the
effect of the inner diameter thereof. Obviously, this invention is
applicable to a tri-potential type electron gun.

Toshiba, "Blackstripe Vertical Stripe Screen Colour Picture Tube", 1973.Claims:I
claim: 1. In a cathode ray tube including a faceplate and a shadow
mask containing an array of vertically oriented slotted apertures for
restricting electron beams directed there through to impinge upon and
excite selected areas of phosphor material on said faceplate, a viewing
screen comprising:

a
horizontally repetitive pattern of sets of three vertically oriented
stripes of phosphor material extending vertically across and coating the
inside surface of said faceplate, each stripe within a set being of
different phosphor material so as to emit a different color when excited
by the corresponding one of the three electron beams passing through
the associated aperture in said shadow mask, and

a
layer of light absorbing material coating the inside surface of said
faceplate and containing a vertical and horizontal array of vertically
oriented slotted openings, said stripes and openings being juxtaposed so
that said openings define viewable portions of said stripes, each
viewable portion being totally surrounded with light absorbing material,

said
openings and stripes being aligned with the apertures in said shadow
mask so that a corresponding one of said three electron beams is allowed
to impinge upon each viewable portion,

the
vertical dimension of each opening being greater than the vertical
dimension of that part of said viewable portion excited by the electron
beam impinging thereupon, such that a positive vertical guardband is
provided, and

the
horizontal dimension of each opening being less than the horizontal
dimension of the impinging electron beam, such that a negative
horizontal guardband is provided.2.
In a cathode ray tube including a faceplate and a shadow mask
containing an array of vertically oriented slotted apertures for
restricting electron beams directed therethrough to impinge upon and
excite selected areas of phosphor material on said faceplate, a viewing
screen comprising:

a
series of vertically oriented stripes of phosphor material extending
across and coating the inside surface of said faceplate, the phosphor
material of horizontally successive stripes differing in a repetitive
pattern so as to emit different colors within each pattern when excited
by electron beams, and

a
layer of light absorbing material coating the inside surface of said
faceplate in the form of a matrix comprising vertical stripes of
material interposed between the phosphor stripes and horizontal spans of
material crossing said phosphor stripes,

the vertical stripes and horizontal spans of light absorbing material defining the viewable portions of said phosphor stripes,

the
vertical dimension of said horizontal spans being less than or equal
to the vertical region of each phosphor stripe between vertically
adjacent beam landings not excited by said electron beams, such that a
zero to positive vertical guardband is provided for each viewable
portion,

the
horizontal dimension of the vertical stripes of light absorbing
material being greater than the horizontal separation between
horizontally adjacent phosphor stripes, such that a negative horizontal
guardband is provided for each viewable portion.3.
In a cathode ray tube including a faceplace and a shadow mask
containing an array of vertically oriented slotted apertures for
restricting electron beams directed therethrough to land upon and excite
selected areas of phosphor materials on said faceplate, a viewing
screen comprising:

a
layer of light absorbing material coating the inside surface of said
faceplate and comprising a web containing an array of vertically
oriented slotted openings therein, there being a unique set of three
horizontally spaced openings for each aperture of said shadow mask
aligned to receive the electron beams passing through said aperture, and

a
layer of phosphor material coated on the inside surface of said
faceplate within the boundaries of said openings, there being a
different phosphor material for each of the openings of a set so as to
emit a different color when excited by the electron beam impinging
thereupon,

the
height of said web between vertically adjacent sets of openings being
less than or equal to the vertical distance between vertically adjacent
beam landings to provide a zero to positive vertical guardband for
each phosphor area,

the
width of said web between horizontally adjacent openings being greater
than the horizontal distance between horizontally adjacent beam
landings to provide a negative horizontal guardband for each phosphor
area.Description:

This
invention relates to cathode ray tube screens, and more particularly
to black matrix screens for color television picture tubes employing
slotted aperture masks and a process for fabricating such screens.

Manufacturers
of cathode ray tubes of the color television picture tube type have
recently begun employing aperture masks having slotted apertures instead
of the more conventional circular apertures in order to achieve
greater electron beam transmission through the mask, since an array of
slots in an aperture mask allows the mask geometrically to be
fabricated with more total open area than the same size mask containing
round or circular apertures. The slotted apertures are typically
arranged in vertical columns on the mask, each column being comprised
of a plurality of slotted apertures. Since more electrons can impinge
on the phosphor regions of the screen in a tube of this type than of
the circular aperture, mask type, a brighter picture results. Unlike
the circularly-configured phosphor regions on the screen of a tube
employing an aperture mask having circular apertures, however, the
phosphor regions on the screen of a tube employing an aperture mask
having slotted apertures are formed in a pattern of adjacent vertical
stripes, typically with each stripe running continuously from the top
of the screen to the bottom.

Black
matrix tubes have also become widely popular as of late, both in
circular aperture mask tubes and slotted aperture mask tubes. As seen
from the viewing side of the screen of circular aperture mask tubes, the
black matrix material completely surrounds each circular phosphor dot,
serving to improve image contrast by absorbing ambient light that
might otherwise be reflected by the screen. Also as seen from the
viewing side of the screen of slotted aperture mask tubes, each
vertical phosphor stripe is separated from the adjacent vertical
phosphor stripe by a stripe of black matrix material running from the
bottom to the top of the screen.

In
fabricating screens for conventional slotted aperture mask tubes of
the black matrix type, a photoresist material coated over the inside
surface of a tube faceplate is exposed in a so-called lighthouse to
actinic radiation in a pattern corresponding to the pattern of matrix
openings ultimately to be formed on the screen. This radiation is
transmitted through the slotted apertures in the mask before impinging
on the photoresist material. The actinic light source used in this
fabrication process is linearly-elongated in a direction parallel to
the columns of slots in the aperture mask in order to permit the black
matrix material to be formed with a pattern of vertically and
horizontally-aligned, vertically-oriented slots extending between the
top and bottom of the screen. The phosphor stripes are thereafter
deposited so that phosphor of a predetermined color emission
characteristic, respectively, is deposited on the faceplate through a
predetermined slot, respectively. Three different phosphor materials
are conventionally deposited in a horizontally-repetitive pattern.

When
a screen formed in the aforementioned manner is operated in a color
television picture tube, parts of each of the phosphor stripes are not
excited by the electron beams, since electrons are blocked by the webs
of the mask between vertically-adjacent slots. These parts of the
stripes, therefore, are essentially useless in producing images, since
they provide no illumination on the face of the tube as a result of
direct bombardment by primary electrons. Moreover, the phosphor material
in these regions adds to overall reflectivity of the screen and hence
has a deleterious effect on image contrast. To overcome this problem,
the present invention contemplates substituting black matrix material to
be seen from the viewing side of the screen to avoid reflection from
the parts of the phosphor stripes not excited by the electron beams.
This may be accomplished by using a source of actinic radiation for
producing slotted openings in the black matrix material that is of
shorter length than the linear source of actinic radiation for producing
the phosphor stripes. The resulting increase in area of black matrix
material serves to reduce screen reflectivity and enhance contrast of
the displayed images. Moreover, by controlling vertical size of the mask
webs between vertically-adjacent openings in the black matrix
material, either a positive guardband or negative guardband mode of
operation in the vertical direction may be achieved.

Accordingly,
one object of the invention is to provide a new and improved color
television picture tube of the black matrix type exhibiting reduced
screen reflectivity and enhanced image contrast.

Another
object is to provide a color television picture tube of the slotted
aperture mask type having a screen, as seen from the viewing side,
formed of a plurality of vertically-oriented linear phosphor regions
completely surrounded by black matrix material.

Another
object is to provide a black matrix color television picture tube of
the slotted aperture mask type capable of operating in a positive or
negative guardband mode of operation in the vertical direction.

A
further object is to provide a black matrix color television picture
tube wherein the vertical guardband of the matrix is controlled to
enhance image contrast without reducing image brightness.

Another
object is to provide a method of fabricating a color television
picture tube of the black matrix type wherein exposures to different
levels of actinic radiation are employed sequentially in forming the
picture tube screen.

Briefly,
in accordance with a preferred embodiment of the invention, a viewing
screen is provided for a cathode ray tube. The tube includes a
faceplate and employs a shadow mask containing an array of
vertically-oriented slotted apertures for restricting electron beams
directed therethrough to impinge on, and excite, selected areas of
phosphor material on the faceplate. The viewing screen comprises a
layer of light-absorbing material coated over the inside surface of the
faceplate, with the layer including a pattern of vertically-elongated
openings therein, and a plurality of vertically-oriented stripes of
phosphor material arranged such that horizontally successive stripes
are comprised of different phosphor materials according to a repeating
pattern. Each of the stripes, respectively, is coated over
substantially the entire area of all the elongated openings situated
essentially in separate vertical alignment, respectively.

In
accordance with another preferred embodiment of the invention, a
method of forming on the faceplate of a cathode ray tube a viewing
screen for a high contrast color television picture tube of the slotted
aperture mask, black matrix type is described. The method comprises
forming a first layer of photosensitive material on the inside surface
of the faceplate and exposing the photosensitive material to actinic
radiation through slotted apertures in the mask from a first linear
radiation source of predetermined dimension along its longitudinal
axis. The longitudinal axis of the first source is maintained
substantially parallel to the longitudinal axis of the slotted
apertures. The unexposed regions of the first layer of photosensitive
material are then removed, and a layer of black matrix material is
formed atop the first layer of photosensitive material and the inside
surface of the faceplate. The exposed regions of the first layer of
photosensitive material and the black matrix material coated thereon
are next removed, leaving openings in the black matrix material. A
second layer of photosensitive material is formed atop the black matrix
material coated on the inside surface of the faceplate and atop the
exposed portions of the inside surface of the faceplate. The second
layer of photosensitive material carries a phosphor material either
coated thereon or mixed therein, emitting a characteristic color of
light when excited by electrons. This is followed by exposing the
second layer of photosensitive material to actinic radiation through
the slotted apertures from a second linear radiation source of
dimension along its longitudinal axis exceeding the predetermined
dimension, the longitudinal axis of the second source also being
substantially parallel to the longitudinal axis of the slotted
apertures. The unexposed regions of the second layer of photosensitive
material are then removed. In this fashion, phosphor material is
applied over the inside surface of the faceplate in registry with the
openings in the black matrix layer. If desired, the phosphor material
may be applied in the form of vertical stripes extending between the
top and bottom of the screen by increasing the length of the second
radiation source, increasing the duration of exposure therefrom, or a
combination of both !

Toshiba Corporation (Japanese: 株式会社東芝 Kabushiki-gaisha Tōshiba) is a Japanese
multinational
conglomerate corporation, headquartered in Tokyo, Japan. The company's
main business is in infrastructure, consumer products, electronic
devices and components.
Toshiba-made Semiconductors are among the Worldwide Top 20 Semiconductor Sales Leaders. In 2009, Toshiba
was the world's fifth largest personal computer vendor, after
Hewlett-Packard of the U.S., Dell of the U.S., Acer of Taiwan, and
Lenovo of China.

Toshiba was founded by the merging of two companies in 1939.
One, Tanaka Seisakusho (Tanaka Engineering Works), was Japan's first manufacturer of telegraph equipment and was established by Hisashige Tanaka in 1875.[2]
. In 1904, its name was changed to Shibaura Seisakusho (Shibaura
Engineering Works). Through the first part of the 20th century Shibaura
Engineering Works became a major manufacturer of heavy electrical
machinery as Japan modernized during the Meiji Era and became a world industrial power.
The
second company, Hakunetsusha, was established in 1890 and was Japan's
first producer of incandescent electric lamps. It diversified into the
manufacture of other consumer products and in 1899 was renamed Tokyo Denki (Tokyo Electric).
The merger in 1939 of Shibaura Seisakusho and Tokyo Denki created a new company called Tokyo Shibaura Denki (Tokyo Shibaura Electric) (東京芝浦電気). It was soon nicknamed Toshiba, but it was not until 1978 that the company was officially renamed Toshiba Corporation.
The
group expanded strongly, both by internal growth and by acquisitions,
buying heavy engineering and primary industry firms in the 1940s and
1950s and then spinning off subsidiaries in the 1970s and beyond. Groups
created include Toshiba EMI (1960), Toshiba International Corporation
(1970's) Toshiba Electrical Equipment (1974), Toshiba Chemical (1974),
Toshiba Lighting and Technology (1989), Toshiba America Information Systems (1989) and Toshiba Carrier Corporation (1999).
Toshiba
is responsible for a number of Japanese firsts, including radar
(1942), the TAC digital computer (1954), transistor television and
microwave oven (1959), color video phone (1971), Japanese word
processor (1978), MRI system (1982), laptop personal computer (1986),
NAND EEPROM (1991), DVD (1995), the Libretto sub-notebook personal computer (1996) and HD DVD (2005).
In 1977, Toshiba merged with the Brazilian company Semp (Sociedade Eletromercantil Paulista), forming Semp Toshiba.
In
1987, Toshiba Machine, a subsidiary of Toshiba, was accused of
illegally selling CNC milling machines used to produce very quiet
submarine propellers to the Soviet Union in violation of the CoCom
agreement, an international embargo on certain countries to COMECON
countries. The Toshiba-Kongsberg scandal involved a subsidiary of
Toshiba and the Norwegian company Kongsberg Vaapenfabrikk. The incident
strained relations between the United States and Japan, and resulted in
the arrest and prosecution of two senior executives, as well as the
imposition of sanctions on the company by both countries.[3]
The US had always relied on the fact that the Soviets had noisy boats,
so technology that would make the USSR's submarines harder to detect
created a significant threat to America's security. Senator John Heinz of Pennsylvania said "What Toshiba and Kongsberg did was ransom the security of the United States for $517 million."
In
2001, Toshiba signed a contract with Orion Electric, one of the world's
largest OEM consumer video electronic makers and suppliers, to
manufacture and supply finished consumer TV and video products for
Toshiba to meet the increasing demand for the North American market.
The contract ended in 2008, ending 7 years of OEM production with
Orion.
In December 2004, Toshiba quietly announced it would
discontinue manufacturing traditional in-house cathode ray tube (CRT)
televisions. In 2006, Toshiba terminated production of in-house plasma
TVs. Toshiba quickly switched to Orion as the supplier and maker of
Toshiba-branded CRT-based TVs and plasma TVs until 2007. To ensure its
future competitiveness in the flat-panel digital television and display
market, Toshiba has made a considerable investment in a new kind of
display technology called SED.
Toshiba is a diversified
manufacturer and marketer of electrical products, spanning information
& communications equipment and systems, Internet-based
solutions and services, electronic components and materials, power
systems, industrial and social infrastructure systems, and household
appliances.

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Resisting the tide of post-modernity may be difficult, but I will attempt it anyway.

Your choice.........Live or DIE.That indeed is where your liberty lies.

IMPORTANT NOTE: - FRANK SHARP obsoletetellyemuseum.blogspot.comwas founded as a public free WEB Museum to all kind of people and amateur and professional CRT TELEVISION Lovers who enjoy using and/or preserving - restoring vintage CRT Televisions sets, or only curious public who was unaware of that kind of technolgy of the past. The purpose is to provide information about vintage Television Receivers Publicy on the WEB that is generally difficult to locate; all this as a important milestone general worldwide reference for the future, globally in the public interest.obsoletetellyemuseum.blogspot.com does not provide support or parts for any apparatus on this site nor do we represent any manufacturer listed on this site in any way. Catalogs, manuals and any other literature that is available on this site is made available for a historical record only. Please remember that safety standards have changed over the years and information in old manuals as well as the old Television receivers themselves may not meet modern standards. It is up to the individual user to use good judgment and to safely operate old machinery. The obsoletetellyemuseum.blogspot.com web site will assume NO responsibilities for damages or injuries resulting from information obtained from this site. No offer to sell or license — Nothing in this site/Blog may be interpreted or construed as an offer to sell products that is open for acceptance or the grant, conveyance or implication of any license under any copyrights, patents or other industrial or intellectual property rights.

Many topics are permanent, so may be updated to any material, for add or correct info.

Sure Fun Times, A working TV Discovered with a CRT Oscilloscope !

Safety Hazards:

------------------------------------------------------Safety Hazards in Radio and TV Repair,------------------------------------------------------

People who believe they can conquer nature are clueless that the laws of nature are a precondition of their existence. Their weapon is a miserable idea.When man attempts to rebel against the iron logic of Nature, he comes into struggle with the principles to which he himself owes his existence as a man. And this attack must lead to his own doom.

Anyone attempting to repair any electronic equipment who does not fully understand the shock hazards, as well as the fire hazards associated with working with electronic equipment, should not attempt such procedures! Improperly attempted repair can kill you and burn down your house.Devices that plug into the wall can produce a very lethal electric shock as well cause a fire from incorrect or careless repairs both during servicing or later on.Improper repair of battery operated devices can also result in bad consequences for you, the device, and any equipment attached to it.

Why some people do repairs themselved then? If you can do the repairs yourself, the equation changes dramatically asyour parts costs will be 1/2 to 1/4 of what a professional will chargeand of course your time is free. The educational aspects may also beappealing. You also will learn a lot in the process.

Consumer electronic equipment like TVs, computer monitors, microwave ovens, and electronic flash units, use voltages at power levels that are potentially lethal. Even more so for industrial equipment like lasers and anything else that is either connected to the power line, or uses or generates high voltage.

Normally, these devices are safely enclosed to prevent accidental contact. However, when troubleshooting, testing, making adjustments, and during repair procedures, the cabinet will likely be open and/or safety interlocks may be defeated. Home-built or modified equipment, despite all warnings and recommendations to the contrary - could exist in this state for extended periods of time - or indefinitely.

Depending on overall conditions and your general state of health, there is a wide variation of voltage, current, and total energy levels that can kill.

Microwave ovens in particular are probably THE most dangerous household appliance to service. There is high voltage - up to 5,000 V or more - at high current - more than an amp may be available momentarily. This is an instantly lethal combination.

TVs and monitors may have up to 35 kV on the CRTbut the current isn't low - like a wrong legend saying a "couple of milliamps" but relatively high because of the boost circuit technology and transformer design. However, the CRT capacitance can hold a painful charge for a long time. In addition, portions of the circuitry of TVs and monitors as well as all other devices that plug into the wall socket are line connected.This is actually even more dangerous than the high voltage due to the greater current available - and a few hundred volts can make you just as dead as 35 kV!

Electronic flash units and strobe lights, and pulsed lasers have large energy storage capacitors which alone can deliver a lethal charge - long after the power has been removed. This applies to some extent even to those little disposable pocket cameras with flash which look so innocent being powered from a single 1.5 V AA battery. Don't be fooled - they are designed without any bleeder so the flash can be ready for use without draining the battery!

Even some portions of apparently harmless devices like VCRs and CD players - or vacuum cleaners and toasters - can be hazardous (though the live parts may be insulated or protected - but don't count on it!

This information also applies when working on other high voltage or line connected devices like Tesla Coils, Jacobs Ladders, plasma spheres, gigawatt lasers, hot and cold fusion generators, cyclotrons and other particle accelerators, as well as other popular hobby type projects. :-)

In addition, read the relevant sections of the document for your particular equipment for additional electrical safety considerations as well as non-electrical hazards like microwave radiation or laser light. Only the most common types of equipment are discussed in the safety guidelines, below.

SAFETY guidelines:

These guidelines are to protect you from potentially deadly electrical shock hazards as well as the equipment from accidental damage.

Note that the danger to you is not only in your body providing a conducting path, particularly through your heart. Any involuntary muscle contractions caused by a shock, while perhaps harmless in themselves, may cause collateral damage. There are likely to be many sharp edges and points inside from various things like stamped sheet metal shields and and the cut ends of component leads on the solder side of printed wiring boards in this type of equipment. In addition, the reflex may result in contact with other electrically live parts and further unfortunate consequences.

The purpose of this set of guidelines is not to frighten you but rather to make you aware of the appropriate precautions. Repair of TVs, monitors, microwave ovens, and other consumer and industrial equipment can be both rewarding and economical. Just be sure that it is also safe!

Don't work alone - in the event of an emergency another person's presence may be essential.

Always keep one hand in your pocket when anywhere around a powered line-connected or high voltage system.

Wear rubber bottom shoes or sneakers. An insulated floor is better than metal or bare concrete but this may be outside of your control. A rubber mat should be an acceptable substitute but a carpet, not matter how thick, may not be a particularly good insulator.

Don't wear any jewelry or other articles that could accidentally contact circuitry and conduct current, or get caught in moving parts.

Set up your work area away from possible grounds that you may accidentally contact.

Have a fire extinguisher rated for electrical fires readily accessible in a location that won't get blocked should something burst into flames.

Use a dust mask when cleaning inside electronic equipment and appliances, particularly TVs, monitors, vacuum cleaners, and other dust collectors.

Know your equipment: TVs and monitors may use parts of the metal chassis as ground return yet the chassis may be electrically live with respect to the earth ground of the AC line. Microwave ovens use the chassis as ground return for the high voltage. In addition, do not assume that the chassis is a suitable ground for your test equipment!

If circuit boards need to be removed from their mountings, put insulating material between the boards and anything they may short to. Hold them in place with string or electrical tape. Prop them up with insulation sticks - plastic or wood.

If you need to probe, solder, or otherwise touch circuits with power off, discharge (across) large power supply filter capacitors with a 2 W or greater resistor of 100 to 500 ohms/V approximate value (e.g., for a 200 V capacitor, use a 20K to 100K ohm resistor). Monitor while discharging and/or verify that there is no residual charge with a suitable voltmeter. In a TV or monitor, if you are removing the high voltage connection to the CRT (to replace the flyback transformer for example) first discharge the CRT contact (under the insulating cup at the end of the fat red wire). Use a 1M to 10M ohm 1W or greater wattage resistor on the end of an insulating stick or the probe of a high voltage meter. Discharge to the metal frame which is connected to the outside of the CRT.

For TVs and monitors in particular, there is the additional danger of CRT implosion - take care not to bang the CRT envelope with your tools. An implosion will scatter shards of glass at high velocity in every direction. There is several tons of force attempting to crush the typical CRT. Always wear eye protection. While the actual chance of a violent implosion is relatively small, why take chances? (However, breaking the relatively fragile neck off the CRT WILL be embarrassing at the very least.)

Connect/disconnect any test leads with the equipment unpowered and unplugged. Use clip leads or solder temporary wires to reach cramped locations or difficult to access locations.

If you must probe live, put electrical tape over all but the last 1/16" of the test probes to avoid the possibility of an accidental short which could cause damage to various components. Clip the reference end of the meter or scope to the appropriate ground return so that you need to only probe with one hand.

Perform as many tests as possible with power off and the equipment unplugged. For example, the semiconductors in the power supply section of a TV or monitor can be tested for short circuits with an ohmmeter.

Provide a reliable means of warning that power is applied and that high voltage filter capacitor(s) still hold a charge during servicing. For example, solder a neon indicator lamp (e.g., an NE2 in series with a 100K ohm resistor) across the line input and a super high brightness LEDs in series with 100K, 1 W resistors across the main filter capacitor(s).

Use an isolation transformer if there is any chance of contacting line connected circuits. A Variac(tm) (variable autotransformer) is not an isolation transformer! However, the combination of a Variac and isolation transformer maintains the safety benefits and is a very versatile device. See the document "Repair Briefs, An Introduction", available at this site, for more details.

The use of a GFCI (Ground Fault Circuit Interrupter) protected outlet is a good idea but may not protect you from shock from many points in a line connected TV or monitor, or the high voltage side of a microwave oven, for example. (Note however, that, a GFCI may nuisance trip at power-on or at other random times due to leakage paths (like your scope probe ground) or the highly capacitive or inductive input characteristics of line powered equipment.) A GFCI is also a relatively complex active device which may not be designed for repeated tripping - you are depending on some action to be taken (and bad things happen if it doesn't!) - unlike the passive nature of an isolation transformer. A fuse or circuit breaker is too slow and insensitive to provide any protection for you or in many cases, your equipment. However, these devices may save your scope probe ground wire should you accidentally connect it to a live chassis.

When handling static sensitive components, an anti-static wrist strap is recommended. However, it should be constructed of high resistance materials with a high resistance path between you and the chassis (greater than 100K ohms). Never use metallic conductors as you would then become an excellent path to ground for line current or risk amputating your hand at the wrist when you accidentally contacted that 1000 A welder supply!

Don't attempt repair work when you are tired. Not only will you be more careless, but your primary diagnostic tool - deductive reasoning - will not be operating at full capacity.

Finally, never assume anything without checking it out for yourself! Don't take shortcuts!

Many people who mistakenly feel that ‘old technology’ is somehow more user-friendly, in some strange way automatically good - merely because it is old. Don’t be fooled! Approach old equipment with an open and alert mind and realise that a hot chassis, or a resistor line cord, or asbestos insulation, or selenium rectifiers require much more thought and consideration for safety.

Live chassis are indiscriminate in whom they kill and even if you are a thoughtful, careful kind of person, that doesn’t mean the last person who handled the set was.

Vintage radio and television receivers use 'live chassis' techniques, in which the chassis is connected directly to one side of the incoming mains supply. This means they can be lethal to carry out repair or servicing work on, unless the appropriate safety measures are in place.

Another thing about live-chassis sets - live spindles. We’ve touched on this already but it’s worth making the point once more. The shafts of switches and potentiometers fixed to the chassis may well be at chassis potential and thus live. The bakelite or wood cabinet is insulated but these shafts are not, and if someone lost the proper grub screw and replaced a knob using a cheesehead screw, the next person to grip that knob may get a dose of 250 volts. Originally these grub screws were sealed and embedded in wax but you cannot rely on subsequent tinkerers having the same high standards.

Even in more orthodox apparatus standards of insulation were not always as high as they are now. Soldered connections to HT and mains wiring should always have rubber or plastic sleeving but in times gone by this was often omitted (or it may since have perished). Beware too of kinked and frayed braiding on cloth-covered mains cords, particularly when the cord has a dropper conductor.

If you are not satisfied that you fully understand the risks involved in this sort of work, do not proceed any further. Instead seek advice and assistance from a competent technician or engineer.

Whenever you acquire a new treasure there's always a terrific temptation to try it out. With mains-driven equipment that means plugging it in and seeing if it works. Well don't, not until you have made some quick checks.

Before contemplating connecting any unknown receiver to the mains supply, spend a little time inspecting it for signs of missing or loose parts, blown fuses, overheating or even fire damage. Use a meter to check obvious points to ensure no short circuit exists (e.g. across the mains input). If you then decide to apply power keep clear but be observant since an elderly electrolytic might explode! This can be avoided if you can apply power gradually through a variac. Auto-transformers are handy for supplying reduced power to sets being repaired but they are not a substitute for a proper isolation transformer!

If you are working with electricity and your work area has a concrete floor, a rubber mat is essential, particularly during damp weather! Where possible try to arrange a neat working area away from water or central heating pipes. For safety try to arrange that this area is separate from the area occupied by your family. This is emphasised because inadvertently rushing to answer a telephone you might just leave a TV chassis connected to a supply and curious little fingers know nothing of the dangers of electricity - or, for that matter - the lethal vacuum encased within every picture tube!

Many younger enthusiasts may not be aware of the dangers of mishandling tubes, in particular the old round types found in early TVs. When handling these tubes eye protection should be worn and tubes must not be left lying around, they must be stored in boxes. The glass is surprising fragile and can implode without any provocation or warning. Bits of glass flying around at high speed can be deadly. The notes following are inspired by Malcolm Burrell again.

Picture tubes are perhaps one of the most hazardous items in any TV receiver. This is because most are of glass construction and contain a very high vacuum. If you measured the total area of glass in any picture tube then estimated the pressure of air upon it at 14.7lb. per square inch, you would discover that the total pressure upon the device could amount to several tons! Fracturing the glass suddenly would result in an extremely rapid implosion such that fragments of glass, metal and toxic chemicals would be scattered over a wide area, probably causing injury to anyone in close proximity. In modern workshops it is now a rule that protective goggles are worn when handling picture tubes.

The weakest point in most picture tubes is where the thin glass neck containing the electron gun is joined to the bowl. It is therefore essential that you refrain from handling the tube by its neck alone. Once a tube is removed from the receiver hold it vertically with the neck uppermost and one hand beneath the screen with the other steadying the device by the neck.With larger devices it is sometimes easier to grip the peripheral of the screen with both hands.

Until the advent of reinforced picture tubes, most were mounted in the cabinet or on the TV chassis by some form of metal band clamped around the face.Never support the weight of the tube by this band since it has been known for the tube to slide out! Some of the larger tubes are extremely heavy. It may, therefore, be easier to enlist assistance.

Before starting to remove a tube, first discharge the final anode connection to the chassis metalwork and preferably connect a shorting lead to this connection whilst you are working. It might be convenient to keep a spare piece of EHT cable with a crocodile clip at one end and a final anode connector at the other.

Exercise care when removing picture tubes from elderly equipment. You may find that the deflection coils have become stuck to the neck. It is extremely dangerous to use a screwdriver prise them away. Gently heating with a hairdryer or soaking in methylated spirit is safer.

Disposal of picture tubes also requires care. Unless rendered safe they should never be placed in dustbins or skips. Many engineers swipe the necks off tubes in cavalier fashion using a broom handle but this is not recommended. A safer method is to make a hole in the side of a stout carton, preferably one designed to hold a picture tube. The tube is placed in the carton and the neck broken using a broom handle. The carton should then be clearly labelled that it contains chemicals and broken glass!

Therefore people who believe they can conquer nature are clueless that the laws of nature are a precondition of their existence. Their weapon is a miserable idea.When man attempts to rebel against the iron logic of Nature, he comes into struggle with the principles to which he himself owes his existence as a man. And this attack must lead to his own doom.

Think for yourself. Otherwise you have to believe what other people tell you.

For most people thinking is a matter of fortune.A society based on individualism is an oxymoron.Freedom is at first the freedom to starve.A wise fool speaks, because he has something to say.A fool speaks, because he has to say something.A wise fool is silent, because there is nothing to say.A fool is silent, because he has nothing to say.

Resist or regretWork for what's good for our people

Help stem the dark tideStand tall or be beat downFight back or die

The man who does not exercise the first law of nature—that of self preservation — is not worthy of living and breathing the breath of life.

We now live in a nation where doctors destroy health, lawyers destroy justice, universities destroy knowledge, governments destroy freedom, the press destroys information, religion destroys morals and our banks destroy the economy.The globalist argument is that if only we erase distinctions, obliterate identities, put everyone on a level playing field, etc.. we can eliminate war and everyone can be so prosperous and efficient, such great cogs in a well-oiled global machine.There will be no more historical grievances because people will no longer even care, they'll have no connection to the past, no foolish pride in past accomplishments of people totally unrelated to them.A globalized culture, no borders, everyone a citizen of the world.Know this: I will never acquiesce to this corrupt, inhuman, Borg-like vision. The dangerous lunatics who push us towards their globalized "utopia" are my enemy. How exactly all this will play out, whether through wars, or whether we can thwart the globalist agenda peacefully (this is my hope of course) I don't know. But I do know that unless people are willing to fight and die, globalism will win out in the end.The actual crimes committed by the EU against the European peoples are directly in violation of the 1948 UN genocide convention, Article II: (c) Deliberately inflicting on the group conditions of life calculated to bring about its physical destruction in whole or in part; (d) Imposing measures intended to prevent births within the group; (e) Forcibly transferring children of the group to another group.* The man who does not exercise the first law of nature—that of self preservation — is not worthy of living and breathing the breath of life.

TELEVISION HISTORY IN BRIEF

Television history

At 1928 Baird transmits from London to New York, using his mechanical system.with 30 vertical lines. By 1930 it was clear that mechanical television systems could never produce the picture quality required for commercial success. For this reason mechanical system was rapidly succeeded by the electronic TV systems. The first all-electronic American systems in 1932 used only 120 scanning lines at 24 frames per second Since the mid-1930s picture repetition frequency (field rate or frame rate) has been the same as the mains frequency, either 50 or 60Hz according to the frequency used in each country. This is for two very good reasons. Studio lighting generally uses alternating current lamps and if these were not synchronised with the field frequency, an unwelcome strobe effect could appear on TV pictures. Secondly, in days gone by, the smoothing of power supply circuits in TV receivers was not as good as it is today and ripple superimposed on the DC could cause visual interference. If the picture was locked to the mains frequency, this interference would at least be static on the screen and thus less obtrusive.To determine what electronic system to use, the BBC sponsored trial broadcasts by two systems, one by Baird, with 240 lines, and one by EMI with 405 lines. Scheduled electronic television broadcasting began in England in 1936 using 405-line system (lasted until the 1980s in the UK). Germany made their forst TV broadcasts at 1936 olympics using 180-line TV system. Germany also made their TV broadcasts by the fall of 1937 using a 441-line system. Also fFrance tested TV (455 line system). RCA introduced electronic television to the U. S. at the 1939 World's Fair,and began regularly scheduled broadcasting at the same time (525 line system).In 1940 the USA established its 525-line standard. At year 1941 the 525-line standard, still in use today in USA, was adopted.Russia also produced TV sets before the war (240 and 343 line systems).World War Two interrupted the development of television. Immediately after World War Two production of TV sets started in the U.S-In USA there was TV broadcasts and few throusand receivers at 1945. In the early 1950s, two competing color TV systems emerged: CBS sequential color (used color wheel) and RCA dot sequential system. At 1953 color broadcasting officially arrives in the U.S. on Dec. 17, when FCC approves modified version of an RCA system.It calls this new RCA color system "NTSC" color. The first NTSC color TVs were on the marker at 1954.In Europe the TV broadcasts started to use experiment using 625 line system 1950s. This standard is used nowadays throughout Europe. France also tried 819 line system at the same time (this system was in use to 1980s). The rest of Europe opted for 625 lines, a system devised in 1946 by two German engineers, M??ller and Urtel (it appears that the Russians came up independently with a very similar system). The use of PAL color standard started at around 1967 and is still in use. The SECAM color system (used in France) testing started also at 1967. The TV broadcasting history has not ended. The newst thign is digital television. It is expected that terrestrial television will open up billion-dollar opportunities for those companies and organisations best prepared to embrace this new broadcasting era. At 1996 small digital satellite dishes hit the market. They become the biggest selling electronic item in history next to the VCR.

Using TV 24H

TV has something for everyone. Idiots, intellectuals, fans of all sorts. Some people are couch potatoes, watch anything just to sit there and be mindless. That's their problem. Children have always needed to be monitored by their parents. If people gotta a mind for it they could figure out the real news even without the internet and there has always been a library.

Is TV bad in and of itself? The researchers aren’t saying that. But we all know that watching television is a solitary, isolating occupation that keeps you sedentary. Sitting in front of the boob tube reduces the time you have available to exercise, interact with your family, read books, and be outdoors. This new research dovetails with other studies, which have linked excessive TV time to obesity and higher rates of cardiovascular disease.

watching too much television can jeopardize your whole family’s health.

This should be a wake-up call to all adults. Stay active. Go outside. Spend time with your spouse and your children with the television off. Read a book and do crossword puzzles to stimulate your imagination and your brain. Reduce your screen time as much as you can.

The National Cancer Institute researchers suggest that watching TV is a public health issue. The price we are paying for our technology-driven lives may be much higher than we previously realized !

DON'T WATCH TV AT ALL !!

The Propaganda TV Machine a.k.a. The Ministry of Truth delivers The Truth from The Government to the people.

At least, that's what they say. In fact, a Propaganda Machine is only employed by The Empire and used to brainwash people into Gullible Lemmings who believe that everything is all right when in fact, it isn't, and that the very people who could help them are their enemies.

Girl Looking TV.

Happy Times:

Do you remember when a telly looked like a real telly? When it was a piece of furniture that you lavished love on, even polished from time to time ?When it was a piece of somewhat at looking in to ?When it was a piece of Highest tech looking inside ? First, this site is a Digital free, HD free, flat panel, HDMI, China, Turks, Afrika free zone. All in all a wealth of vintage information at your finger tips, a one stop unique experience. So step on in, leave the modern throw-away world behind, travel back in time to a vintage world of repair and enjoy.This site has stirred memories about the watching TV's days on a CRT TUBE television......Childhood memories, your parents getting their first colour tv, a b/w or color portable, perhaps memories of renting or buying your first set remote featured, perhaps your days working in the trade, selling or repairing them....... If you enjoyed this site, found its content left you all misty eyed then just talk about it as it would be very welcome............like the time to recover and restore a set ................and happy reminiscing.

Digital TV in Brief.

Digital TV:

Digital television is a hot topic now.If you have looked at television sets at any of the big electronics retailers lately, you know that Digital TV, or DTV, is a BIG deal right now in the U.S. In Europe Digital TV is also a hot topic, because many countries have started terrestrial digital TV broadcasts and plan to end analogue broadcasts after some years (will take 5-10 years). Satellite TV broadcasts have also shifted very much to digital broadcasts.The main advantage if digital broadcasts are that it does not havethe picture quality problems of analogue TVs (it had it's own videoproblems caused by video compression), it allowes putting more TV channels to same medium (TV channel frequencies and satellites) and it allows new services (like HDTV and interactive multimedia). The digital brodcasts are generally designed to use such modulation that the digital data stream (typically around 20-30 Mbit/s) is modulated to the same bandwidth (around 6 MHz) as the analogue TV broadcasts. The used modulation vary between different media, which means thatdifferent modulation techniques are used in terrestrial transmissions, cable TV and satellite. Different modulations are used because of the different characteristics of those transmission medias. There is not on "digital TV", but several different variations of it in use.The basic technology of digital TV, known as MPEG 2 video compressionand MPEG 2 transmission stream format, is same around the world, butis is used somewhat differently in different standards used in differentcountries.

USA uses ACTS Digital Televisio Standard, which standardizes NTSC format transmissions, HDTV transmission, sound formats and data signal modulation in use. The ATSC MPEG-2 formats for DTV, including HDTV, uses 4:2:0 samling for video signal. The US system uses a fixed power and a fixed maximum bitrate, at which some bits are always transmitted. That rate is typically 19.3 Mb/sec.

Europe uses DVB (Digital Video Broadcasting) standard. This standardallows basically normal PAL resolution transmisssion (vasically HDTVcould be added later but is not yet standardized) with several audio formats, digital data rates and digital signal modulation. There are several different variations fo DVB standard for different media:

DVB-T for terrestrial broadcastsDVB-S for satelliteDVB-C for cable TV

Those different DVB versions varyon the data signal modulation methods, error correction and frequency bands used. DVB and option for some interactive extra services, but thestandardization of this is not ready here yet(there are fire different incompatible interactive servicessystems in use in different countries and by different broadcasters).

The process of transmitting digital TV signal is the following: Analog video/audio - digitisation - MPEG compression - Multiplexing ( youcan now call it digital) - Preparation for transmisson - modulation toanalog carrier.Reception process is the following: Demodulation of analogue carrier - Error correction - Demultiplexing - MPEG decompression - DA conversion to get analogue signal (unless you use digital display). The analoguie video signal that gets digitized can be practically from any video source, for example produced with old analogue video production equipment and distributed with a video tape. In high-end system the information is analogue only in the image sensor on the video camera, and from this on the signal gets digitally processed. In many real-life TV production systems the reality is something between those two extremes.

At least in Europe, the signal level requirements for DVB-T are well below the analog requirements, so the transmitter power is much less than on the analog side. In the NorDig recommendation the minimum received signal level for 64QAM, 7/8 code rate with a Rayleigh fading path and 8 dB receiver noise figure would be -64 dBm. With other code rates, modulations and fading mechanisms, the requirement is lower. Many receivers can perform much better at conditions where there is no fading (a quasi error free less than one uncorrected error/hour signal even at 27 dBuV (-82 dBm) with 64QAM and 8 MHz channel width). For analog signals, the recommended level is more than 1 mV (+60 dBuV, -49 dBm). While the ERP can be at least 10 dB lower than analog, the question of power consumption is more complicated, since COFDM with 64QAM carriers require a quite good linearity, which may affect the efficiency and hence power consumption.

Digital TV system in use in USA

The FCC mandate to change our broadcast standards from NTSC analog to ATSC digital broadcasting (DTV) is big bold move, requiring changes in everything from the way the studios shoot video, the format that's transmitted, to the equipment we use to receive and watch broadcastsDTV (digital TV) applies to digital broadcasts in general and to the U.S. ATSC standard in specific. The ATSC standard includes both standard-definition (SD) and high-definition (HD) digital formats. The notation H/DTV is often used to specifically refer to high-definition digital TV. The federal mandate grants the public airwaves to the broadcasters to transmit digital TV in exchange for return of the current analog NTSC spectrum, allowing for a transition period in the interim. At the end of this period scheduled for 2006, broadcasters must be fully converted to the 8VSB broadcast standard. Digital Television ("DTV") is a new broadcast technology that will transform television. The technology of DTV will allows TV broadcasts with movie-quality picture and CD- quality sound and a variety of other enhancements (for example data delivery). With digital television, broadcasters will be able to offer free television of higher resolution and better picture quality than now exists under the current mode of TV transmission. If broadcasters so choose, they can offer what has been called "high definition television" or HDTV, television with theater-quality pictures and CD-quality sound. . Alternatively, a broadcaster can offer several different TV programs at the same time, with pictures and sound quality better than is generally available today. HDTV (high-definition TV) encompasses both analog and digital televisions that have a 16:9 aspect ratio and approximately 5 times the resolution of standard TV (double vertical, double horizontal, wider aspect). High definition is generally defined as any video signal that is at least twice the quality of the current 480i (interlaced) analog broadcast signal. There are 18 approved formats for digital TV broadcasts, but only two (720p/1080i) are proper definition of the term HDTV. The advent of high definition has allowed monitors to read images differently, either in standard interlaced format or progressively. Sets that do not have any decoding capabilities but can display the high-resolution image is often labeled as "HD-Ready" a term that describes 80% or more of the Digital TVs on the market. HDTV displays support digital connections such as HDMI (DVI) and IEEE 1394/FireWire, although standardization is not finished. HDTV in the US is part of the ATSC DTV format. The resolution and frame rates of DTV in the US generally correspond to the ATSC recommendations for SD (640x480 and 704x480 at 24p, 30p, 60p, 60i) and HD (1280x720 at 24p, 20p, and 60p; 1920x1080 at 24p, 30p and 60i). In addition, a broadcaster will be able to simultaneously transmit a variety of other information through a data bitstream to both enhance its TV programs and to provide entirely new services. The technical specifications of USA DTV system is defined in ACTS Digital Television Standards.

Digital TV in Europe

Digital TV brodacasting in Europe is done according to DVB standards. DVB technology has become an integral part of global broadcasting, setting the global standard for satellite, cable and terrestrial transmissions and equipment. There are three versions of DVB in use: DVB-S, DVB-C and DVB-T.DVB-T is a flexible system allowing terrestrial broadcastersto choose from a variety of options to suit their various service environments. This allows the choice between fixed roof-top antenna, portableand even mobile reception of DVB-T services. Broadly speaking the trade-off in one of service bit-rate versus signal robustness.

DVB-T network is very flexible. Having many transmitters all on the same frequency is not a problem for the used COFDM based system. COFDM has been chosen and designed to minimise the effects of multipath in obstructed reception areas. In fact multipath signals can significantly improve the overall received signal with no adverse effects. These properties are particularly valuable for radio cameras and mobile links. DVB-T because of its unique design which allows single frequency networks (SFN). This means that many transmitters along the planned routes can transmit on the same frequency. It is also possible to use simple gap fillers that amplify and retransmit the signal. In-air digital TV broadcasts in Europe use DVB-T. 8 MHz of bandwidth may be used to provide a 24 Mbps digital transmission path using Coded Orthogonal Frequency Division Multiplexing (COFDM) modulation (theoretical maximum 31.67 Mbits for 8 MHz bandwidth). In cases where less bandwidth is available (6 or 7 MHz), the data rate is somewhat lower (around 20 Mbit/s).

DVB-C does the same function as DVB-T, but the modulation used in this system is optimized to operate well in cable TV networks. The modulation used in DVB-C is QAM. Systems from 16-QAM up to 256-QAM can be used, but the system centres on 64-QAM, in which an 8MHz channel can accommodate a physical payload of about 38 Mbit/s. Digital cable TV in Europe uses DVB-C. The DVB standard for the cable return path has been developed jointly with DAVIC, the Digital Audio Visual Council. The specification uses Quadrature Phase Shift Keying (QPSK) modulation in a 200kHz, 1MHz or 2MHz channel to provide a return path for interactive services (from the user to the service provider) of up to about 3Mbit/s. The path to the user may be either in-band (embedded in the MPEG-2 Transport Stream in the DVB-C channel) or out-of-band (on a separate 1 or 2MHz frequency band).

DVB-S is the satellite version of DVB. Satellite transmission has lead the way in delivering digital TV to viewers. Established in 1995, the satellite standard DVB-S is the oldest DVB standard, used on all six major continents. QPSK modulation system is used, with channel coding optimised to the error characteristics of the channel. A typical satellite channel has 36 MHz bandwidth, which may support transmission at up to 38 Mbps (assuming delivery to a 0.5m receiving antenna) using Quadrature Phase Shift Keying (QPSK) modulation. 16 bytes of Reed Solomon (RS) coding are added to each 188 byte transport packet to provide Forward Error Correction (FEC) using a RS(204,188,8) code. For the satellite transmission, the resultant bit stream is then interleaved and convolutional coding is applied.

The core of the DVB digital data stream isthe standard MPEG-2 "data container",which holds the broadcast and service information.This flexible "carry-all" can containanything that can be digitised, includingmultimedia data. The MPEG-2 standards define how to format the various component parts of a multimedia programme (which may consist of: MPEG-2 compressed video, compressed audio, control data and/or user data). It also defines how these components are combined into a single synchronous transmission bit stream. The process of combining the steams is known as multiplexing. The multiplexed stream may be transmitted over a variety of links, standards / products.Each MPEG-2 MPTS multiplex carries a number of streams which in combination deliver the required services. A typical data rate of such multiplex is around 24 Mbps for terrestrial brodcasts.

European DVB systems currently transmit only standard definition TV signals and set top boxes also handle only normal TV resolution. It would be possible to transmit HDTV signals on DVB data stream, but those broadcasts have not yet started in any wide scale. There is one satellite broadcater that broadcasts HDTV DVB signals in Europe (some cable TV operators carry that signal on their cable).

Many DVB-T integrated TV sets, and some set top boxes, in the Europe come with a Common Interface slot - which is pretty much the same form-factor as a PC Card (aka PCMCIA) used in PC laptops. This CI slot accepts a Conditional Access Module, in the same way that DVB-S receivers do, which implements at least one (some can do more than one) decryption algorithm. This CAM may also, itself, have a smart card slot to accept a consumer subscription card to authorise decryption - you plug your smartcard into your CAM and your CAM into the CI slot in your receiver/IDTV. Some DVB receivers have an integrated CAM (in the case of some receivers this is implemented purely in software, with no extra hardware required) rather than a CI slot to plug in a 3rd party device. With these type of receivers you just plug in the smart card and don't have to worry about CI slots and buying CAMs. So there is an interface standard for DVB - but different broadcasters can chose different encryption schemes, requiring different CAMs for decryption.

DVB Standards and related documents are published by the European Telecommunications Standards Institute (ETSI). These include a large number of standards and technical notes to complement the MPEG-2 standards defined by the ISO.

There are few different standard how interactive TV functionaly is implemented in DVB-systems in use in differenct countries. DVB-MHP is one gaining some acceptance. Multimedia Home Platform (MHP) is the open middleware system designed by the DVB Project (www.dvb.org).